1. Field of the Invention
This invention relates generally to mounting and connecting integrated circuit chip dice to a printed circuit substrate, and in particular, to an apparatus and method for mounting and connecting the chip dice to a Mini-Board that may be adapted to attach and connect into a plurality of different types of printed circuit board systems.
2. Description of the Related Technology
Packaging techniques for integrated circuits have been developed in the past in an attempt to satisfy demands for miniaturization in the semiconductor industry. Improved methods for miniaturization of integrated circuits enabling the integration of millions of transistor circuit elements into single integrated silicon embodied circuits, or chips, have resulted in increased emphasis on methods to package these circuits in space efficient, yet reliable and mass producible packages.
Integrated circuits are created from a silicon wafer using various etching, doping and depositing steps that are well known in the art of fabricating integrated circuit devices. A silicon wafer may be comprised of a number of integrated circuit dice that each represent a single integrated circuit chip die. Ultimately, the chip may be packaged by transfer molding plastic encasement around the die with a variety of pin-out or mounting and interconnection schemes, or the die may be directly attached and connected to a printed circuit board substrate.
Directly mounting integrated circuit chip dice onto printed circuit boards, commonly called Chip-On-Board (COB), and the connection of the chip dice to the printed circuit board substrate conductors by using direct wire bonding, create significant technological problems for the electronic system manufacturer. As the chip densities and sophistication of circuitry contained therein became greater, the precision required in mounting and connecting the chip die to the printed circuit board substrate and conductors become critical.
Mounting precision is important because resolution of the circuit conductor traces on the printed circuit board have to properly align with the integrated circuit chip die connection pads. The chip die pads would then be electrically connected to the printed circuit board conductors by means well known in the art such as, for example, wire bonding.
The mounting precision required and dimensional tolerances, however, are not easily achieved in a typical electronic systems manufacturing environment. The equipment required for COB fabrication for very fine tolerances is often beyond the means of most companies.
Another disadvantage of using COB for fabricating electronic systems is when there is a defective integrated circuit chip connected on the printed circuit board substrate. The printed circuit board often is damaged during service, and replacement of a new integrated circuit chip becomes extremely difficult during rework, even when proper equipment is available.
What is needed is a method and apparatus that allows mounting a plurality of integrated circuit chip dice to printed circuit boards having various levels of complexity and sophistication, ease in testing, and a relatively easy way of repairing or replacing a defective die.